The present invention relates to metal cutters, and the like, and in particular to a milling cutter having at least one blade.
Milling cutters are used extensively in high speed machining operations, and typically include a cutter body, with removable, indexable insert blades. One such milling cutter is disclosed in my prior U.S. Pat. No. 4,573,831, issued Mar. 4, 1986, entitled CUTTER BLADE, which is hereby incorporated by reference.
A problem has been encountered with the use of such milling cutters in the machining of high carbon steels, such as die steels, and the like. In order to achieve improved cutting efficiency, it is necessary to reduce the relief or clearance space between the insert blades and the workpiece. Heretofore, the clearance space has been reduced by tilting the trailing edge or heel of the insert blades radially outwardly, as shown in a greatly exaggerated condition in FIG. 9 of the appended drawings. However, such a tilted orientation of the insert blades in the cutter body causes the heels of the blades to contact and rub or drag against the workpiece as the cutter body rotates. This heel drag would make cutting the metal an impossibility.
Those problems noted above are particularly prevalent when using relatively thick, indexable insert cutters. Also, the difficulties experienced in reducing the clearance space to provide improved cutting efficiency for die steels and the like is exacerbated as the diameter of the cutter body becomes smaller, as in the case of end mills.